The invention relates to telephony headset amplifiers, and in particular to headset amplifiers for use with computers.
Speech recognition software is a tool for increasing office productivity, particularly for entering text in word processing applications with personal computers. Such software performs best when voice input is provided via a "close talking" headset microphone, i.e., a microphone with acoustic cancellation of background noise. The microphone is connected to the corresponding input connector of the computer sound card. It is evident that by wearing a headset, dictation becomes a hands-free operation and is therefore valuable for individuals with limited use of hands or arms. When the person dictating text via the headset microphone wishes to use the telephone, an awkward situation develops, that of having to remove the headset in order to use the telephone handset. The application of headsets in telephony is common. The acoustic and electrical characteristics of headsets for speech recognition and telephony, however, are different.
One headset is not usable for both applications unless it is first connected to an interface apparatus, which then provides suitable outputs to the personal computer sound card and to the telephone. An exemplary product is Plantronics model CATM10. The Plantronics apparatus offers the conventional telephony headset amplifier functions such as receive volume adjustment, microphone mute, headset-handset selection, and also includes a transfer switch. One switch position enables the path to the telephone and totally opens the path to the computer. The opposite occurs in the second position.
While such prior art headsets provide a solution using only one headset for telephony and speech recognition, it falls short in one important call center application: when a customer calls in to place an order, the operator should be able to repeat the information into the order processing software. In other words, the called party (the operator) must be able to listen while dictating to the computer, remaining inaudible to the calling party (the customer). The exemplary prior art product also includes a six-position multi-pole compatibility switch with which the user can match the amplifier with the type of telephone it is connected to. Such telephones may have three or four wire handsets with electret, dynamic or carbon microphones with differing impedances and signal levels hence the need for a compatibility switch.
It is alternatively possible to construct a headset with a common headband, but two with independent sets of transducers, for example, a "left" side with the appropriate microphone, speaker and cable connected to the computer and a "right" side with the corresponding parts for the telephone. The resulting headset, although electrically correct will be inconveniently burdened with two microphone booms and two cables.